Former Argentine President Isabel Peron has been conditionally released in Madrid following her arrest on an international warrant.

Spanish police acting at the request of an Argentine federal judge arrested the former president at her home Friday. Authorities say the 75-year-old Peron will have to appear in court every two weeks pending a decision on extraditing her to Argentina.

Argentine officials say they want to question Mrs. Peron about the disappearance of leftist Hector Aldo Gallego, a political activist, in February 1976.

They also are seeking answers about three decrees that she signed calling on the armed forces to crack down on "subversive elements."

Human rights groups applauded the judge's action. One activist said the decision to question Mrs. Peron would bring light to a part of Argentine history he said was "dark, obscure and papered over."

Mrs. Peron was sworn in as president in 1974 following the death of her husband, three-time president Juan Peron. During her brief period in power, Argentina was wracked by violence involving leftist guerrillas and death squads. She was deposed in a 1976 military coup.

The warrant comes as investigators revive probes of a death squad known as the Argentine Anti-Communist Alliance, or "Triple A." The squad operated under Mrs. Peron and carried out kidnappings and murders, targeting leftist groups such as the Montoneros guerrillas.